Catheter tunneler adapter

ABSTRACT

A catheter tunneling adapter including a longitudinal body having a distal end and a proximal end and a passageway extending from an entrance at the proximal end to an exit at the distal end. The passageway has a first hemisphere and a second hemisphere with the first hemisphere defining a generally unobstructed first passageway portion from the entrance to the exit. A guide ramp is positioned within the second passageway and tapers towards the first hemisphere moving from the proximal end to the distal end. The ramp defines a longitudinal notch therethrough such that a second passageway portion extends from the entrance to the exit.

This application claims the benefit of U.S. Provisional Appln. No.61/723,852 filed on Nov. 8, 2012, the contents of which are incorporatedherein by reference.

FIELD OF THE INVENTION

This invention relates to medical devices and more particularly to anadapter for a vascular catheter to facilitate subcutaneous tunnelingthereof.

BACKGROUND OF THE INVENTION

Catheters for the introduction or removal of fluids may be located invarious venous locations and cavities throughout the body of a patientfor introduction of fluids to the body or removal of fluids from thebody. Such catheterization may be performed by using a single catheterhaving multiple lumens. A typical example of a multiple lumen catheteris a dual lumen catheter in which one lumen introduces fluid and theother lumen removes fluid. An example of such a multiple catheter is theSPLIT-CATH® catheter, sold by Medical Components, Inc. of Harleysville,Pa.

Generally, to insert any catheter into a blood vessel, the vessel isidentified by aspiration with a long hollow needle in accordance withthe well known Seldinger technique. When blood enters a syringe attachedto the needle, indicating that the vessel has been found, a thin guidewire is then introduced, typically through a syringe needle or otherintroducer device into the interior of the vessel. The introducer deviceis then removed, leaving the end portion of the guide wire that has beeninserted into the vessel within the vessel and the opposing end of theguide wire projecting beyond the surface of the skin of the patient. Atthis point, several options are available to a physician for catheterplacement. The simplest is to pass a catheter into the vessel directlyover the guide wire. The guide wire is then removed, leaving thecatheter in position within the vessel. However, this technique is onlypossible in cases where the catheter is of a relatively small diameter,made of a stiff material, and not significantly larger than the guidewire. For example, this technique may be used to insert small diameterdual lumen catheters into a patient. If the catheter to be inserted issignificantly larger than the guide wire, a dilator device is passedover the guide wire to enlarge the hole. The dilator device is thenremoved, and the catheter is then passed over the guide wire into thevessel. The guide wire is then removed.

For chronic catheterization, in which the catheter is intended to remaininside the patient for an extended period of time, such as for weeks oreven months, it is typically desired to subcutaneously tunnel thecatheter using various tunneling techniques. The catheter is typicallytunneled into the patient prior to inserting the catheter into thepatient's vein. However, depending on the patient or the implantingsurgeon's skill, there may be times when it is more advantageous toperform the tunneling after the catheter is implanted in the patient.For some catheters, though, such as multiple lumen catheters with a huband with bonded luers on the proximal ends of the catheters, it isimpractical to perform the tunneling after the catheter is installed inthe patient.

An alternative installation procedure is available for installing thecatheter that better suits the patient's needs and the surgeon's skills.Such an alternative catheter assembly is the multi-lumen catheterdisclosed in U.S. patent publication No. US 2004/0092863. In order to beable to perform the tunneling after the distal end of the catheterassembly is inserted into the patient (termed retrograde tunneling), theproximal ends of each catheter must be attached to a tunneler deviceadapted to pull the proximal end of each catheter through the tunnel.After tunneling, the proximal ends of the catheters must be disconnectedfrom the tunneler device and then connected to a catheter hub.

U.S. patent publication Nos. US 2004/0176739 and 2008/0097409,incorporated by reference, each describe a catheter tunneling adapterthat allows for the simultaneous tunneling of the proximal ends of eachcatheter in a multi-lumen catheter assembly. In each case, the adapteris comprised of a generally elongated body having a distal end and aproximal end and a longitudinal axis extending therethrough between thedistal end and the proximal end. The proximal end includes a connectorfor connecting a catheter tunneler thereto. The distal end comprises aconnector for connecting a plurality of catheter lumens thereto. Thepublications also provide a method of inserting a catheter having aplurality of lumens into a patient. The method is comprised of insertinga distal end of each of the plurality of lumens into a blood vessel inthe patient; connecting a proximal end of each of the plurality oflumens to a tunneling device; forming a subcutaneous tunnel with thetunneling device; drawing the proximal ends of each of the plurality oflumens simultaneously through the tunnel; disconnecting the tunnelingdevice from the proximal ends of each of the plurality of lumens; andconnecting the proximal ends of each of the plurality of lumens to acatheter hub component. Such a catheter hub component may be asdisclosed in U.S. Pat. No. 7,261,708 or U.S. Pat. No. 6,969,381, each ofwhich discloses a hub that is mountable to a catheter's proximal endafter tunneling thereof has been performed.

SUMMARY OF THE INVENTION

The present invention is an adapter that at its distal end is securableonto the ends of two (or more) lumens of a catheter to facilitateimplantation thereof in a patient's vasculature, and is securable at itsproximal end to, sequentially, a flushing syringe, a stylet and also atunneler, so that while connected to the catheter's proximal end itpermits releasable connection with a stylet for the guide wire to permitimplantation of the distal portion in place in the vasculature, and thenwith a tunneler for subcutaneous tunneling of the proximal portion ofthe catheter. In at least one embodiment, the catheter tunneling adapterincludes a longitudinal body having a distal end and a proximal end anda passageway extending from an entrance at the proximal end to an exitat the distal end. The passageway has a first hemisphere and a secondhemisphere with the first hemisphere defining a generally unobstructedfirst passageway portion from the entrance to the exit. A guide ramp ispositioned within the second passageway and tapers towards the firsthemisphere moving from the proximal end to the distal end. The rampdefines a longitudinal notch therethrough such that a second passagewayportion extends from the entrance to the exit.

In at least one embodiment, the passageway entrance is configured toreceive a portion of a syringe and a fluid expelled from the syringepasses through and exits both the first and second passageway portionsat the distal end of the longitudinal body.

In at least one embodiment, the adapter is adapted for use with acatheter including first and second lumens and the first passagewayportion is aligned with the first lumen and the second passagewayportion is aligned with the second lumen. Furthermore, the passageway isconfigured for passage of a stylet shaft having a given outer diametertherethrough, and the diameter of the first passageway portion isgreater than the given outer diameter and the width of the secondpassageway portion is less than the given outer diameter. In at leastone embodiment, the passageway entrance is configured to receive aportion of a syringe and a fluid expelled from the syringe passesthrough the first passageway portion and flows into the first lumen andalso passes through the second passageway portion and into the secondlumen.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and constitutepart of this specification, illustrate the presently preferredembodiments of the invention, and, together with the general descriptiongiven above and the detailed description given below, serve to explainthe features of the invention. In the drawings:

FIG. 1 is an isometric view of an exemplary adapter in accordance withan embodiment of the present invention,

FIG. 2 is a proximal end view of the adapter of FIG. 1.

FIG. 3 is a cross-sectional view along the line 3-3 in FIG. 2.

FIGS. 4A and 4B are distal end views of exemplary embodiments of theadapter of FIG. 1.

FIG. 5 is an exploded side view illustrating the adapter of FIG. 1 priorto assembly with a catheter and a stylet.

FIG. 6 is a proximal end view of the catheter of FIG. 5 prior toassembly preparation.

FIG. 7 is a proximal view similar to FIG. 6 illustrating the catheterproximal end after it has been prepared for assembly in accordance withan exemplary embodiment of the invention.

FIG. 8 is a partial top plan view of the catheter proximal end afterassembly preparation.

FIG. 9 is an exploded view of an exemplary cutting tool for preparationof the catheter proximal end in accordance with an exemplary embodimentof the invention.

FIG. 10 is a partial plan view of a cutting surface of one of the jawsof the cutting tool of FIG. 9.

FIG. 11 is a side elevation view of the cutting tool of FIG. 9 in anopen position.

FIG. 12 is a side elevation view of the cutting tool of FIG. 9 in aclosed position.

FIG. 13 is an exploded view of another exemplary cutting tool forpreparation of the catheter proximal end in accordance with an exemplaryembodiment of the invention.

FIG. 14 is a partial plan view of a cutting surface of one of the jawsof the cutting tool of FIG. 13.

FIG. 15 is a side elevation view of the cutting tool of FIG. 13 in anopen position.

FIG. 16 is a side elevation view of the cutting tool of FIG. 13 in aclosed position.

FIG. 17 is an exploded side view illustrating the adapter of FIG. 1assembled with a catheter and prior to insertion of a stylet.

FIG. 18 illustrates initial insertion of the stylet into the adapter andcatheter assembly, which are shown in longitudinal cross-section.

FIG. 19 is a view similar to FIG. 18 illustrating the stylet furtherinserted into the adapter and catheter assembly.

FIGS. 20-22 are schematic views illustrating sequentially an exemplarytunneling procedure using the adapter of FIG. 1.

FIG. 23 is a top plan view illustrating the catheter proximal end priorto assembly with an exemplary hub.

FIG. 24 is a view similar to FIG. 23 illustrating the catheter proximalend assembled with an exemplary hub.

DETAILED DESCRIPTION OF THE INVENTION

In the drawings, like numerals indicate like elements throughout.Certain terminology is used herein for convenience only and is not to betaken as a limitation on the present invention. The words “proximal” and“distal” refer to directions away from and closer to, respectively, theinsertion tips of a catheter adapted to connect to the adapter of thepresent invention. The terminology includes the words above specificallymentioned, derivatives thereof, and words of similar import. Thefollowing describes a preferred embodiment of the invention. However, itshould be understood based on this disclosure, that the invention is notlimited by the preferred embodiment described herein.

An adapter 10 in accordance with an exemplary embodiment of the presentinvention is shown in FIGS. 1 to 5. The adapter 10 includes a body 12having a proximal end 14, a distal end 16, and a through passageway 18extending through the body 12 from an entrance 20 at the proximal end 14to an exit 22 at the distal end 16. Recesses 15 may be provided alongthe outer surface of the adapter body 12 to assist in gripping theadapter 10. While the adapter body 12 is preferably formed as a unitaryannular body about the passageway 18, a reference plane RP isillustrated in the drawings and the body will be described with respectto a first hemisphere 12 a and a second hemisphere 12 b for clarity ofdescription. While the reference plane RP is illustrated passing througha central axis of the body 12, it may be closer to the first hemisphere12 a or the second hemisphere 12 b depending on the configuration of thecatheter 50 with which the adapter 10 is to be used. In this way, thefirst hemisphere 12 a and the second hemisphere 12 b do not have to beequivalent and one may have a larger volume than the other and may havea greater inner or outer surface area. It is preferable that the adapter10 is made of soft biocompatible material like polyurethane, such as,for example, PELLETHANE® polyurethane sold by Dow Chemical Co. ofMidland, Mich. and having a durometer such as about 80 A, however, othermaterial may be utilized.

The distal end 16 of the adapter body 12 includes a radially inward step30 which defines a reduced diameter annular connection surface 32 aboutthe distal end of the passageway 18. The connection surface 32 isconfigured to be received in the proximal end of a double lumen catheter50 (see FIGS. 5 and 18). Referring to FIGS. 4A and 4B, longitudinalgrooves 33 extend along each side of the annular surface 32 from thedistal end 16 to the step 30. The illustrated grooves 33 are configuredto receive remaining portions 55, 57 of the lumen divider 56 as will bedescribed hereinafter. Accordingly, the grooves 33 are positionedrelative to the reference plane RP to correspond to the configuration ofthe catheter 50 with which the adapter 10 is to be utilized.Furthermore, as illustrated by comparing the adapters 10, 10′ in FIGS.4A and 4B, the configuration of the adapter body 12, the step 30, theconnection surface 32, 32 a and the guide ramp 40, to be describedbelow, may all be modified to correspond to the configuration of thecatheter. For example, the adapter 10 of FIG. 4A is configured to beutilized with a 15.5 french TITAN® catheter while the adapter 10′ ofFIG. 4B is configured to be utilized with a 16 french SPLIT-CATH®catheter, both sold by Medical Components, Inc. of Harleysville, Pa.

As indicated at 34 in FIGS. 1 and 3, the portion of the connectionsurface 32 in the first hemisphere 12 a is cut away immediatelyproximate the body distal end 16 such that the distal portion 32 a ofthe connection surface 32 is generally semi-annular extending primarilyin the second hemisphere 12 b, although some of the connection surfacedistal portion 32 a may extend into the first hemisphere 12 a. In viewof the cut away portion, the passageway 18 exits the body 12 in thefirst hemisphere 12 a at radial exit 22 a prior to the surface of thedistal end 16.

Referring now to FIG. 3, the through passageway 18 includes a connectionportion 19 extending from the entrance 20. The connection portion 19 isconfigured for connection to various medical devices as will bedescribed in more detail hereinafter. The connection portion 19preferably has a slight taper to assist with such connection. Atransition portion 21 tapers from the connection portion 19 to acommunication portion 23 which extends to the exit 22.

As will be described in more detail below, the passageway 18 facilitatesflushing of both lumens 52, 54 of a catheter 50 with saline or the like,guides positioning of a stylet 70 into the catheter 50, and provides aconnection to a tunneler or the like. With reference to FIG. 5, anexemplary stylet 70 includes a hub 72 from which extends an engagementprojection 74 and a relatively stiff, elongate stylet shaft 76sufficiently long to extend completely through a first lumen 52 of thecatheter 50 and beyond its distal tip. As is known in the art, thestylet 70 allows a guide wire (not shown) to be easily insertabldethrough the stylet and thus through the adapter and the catheter, foruse in vascular placement of the catheter's distal portion. During use,the frustoconical engagement projection 74 enters into the adapter'sentrance 20 and is preferably frictionally engaged within the connectionportion 19 for releasable connection with the adapter 10.

To ensure the stylet shaft 76 extends into the first lumen 52 and notthe second lumen 54, a guide ramp 40 is defined in the passageway 18,generally in the second hemisphere 12 b. The guide ramp 40 tapersradially inward beginning from the transition portion 21 and extendingthrough the second hemisphere 12 b of the communication portion 23 tothe exit 22. With the guide ramp 40 generally in the second hemisphere12 b, the communication portion 23 a in the first hemisphere 12 a isdefined as a generally circular cross-section with a diameter d (seeFIG. 4A). The diameter d is greater than an outer diameter t of thestylet shaft 76 (see FIG. 5) to be used with the adapter 10 such thatthe stylet shaft 76 can pass through the first hemisphere communicationportion 23 a. Configurations other than circular cross-section may beutilized provided a desired stylet shaft may pass through the firsthemisphere communication portion 23 a.

The guide ramp 40 includes a notch 42 extending the length thereofbetween opposed ramp sides 43 and 44. The notch 42 has a width w anddefines the second hemisphere communication portion 23 b. The width w isless than the outer diameter t of the stylet shaft 76 such that thestylet shaft 76 can not pass through the second hemisphere communicationportion 23 b, but instead contacts the ramp sides 43 and 44 and isdirected to the first hemisphere communication portion 23 a as shown inFIGS. 18 and 19. As will be described in more detail below, the firsthemisphere communication portion 23 a is aligned with a first catheterlumen 52 while the second hemisphere communication portion 23 b isaligned with the second catheter lumen 54. As such, the configuration ofthe ramp 40 ensures that the stylet shaft 76 will always be directed tothe first catheter lumen 52. Preferably the adapter 10 is positionedrelative to the catheter 50 such that the first catheter lumen 52 is thearterial lumen, however, the adapter may be alternatively positionedsuch that the first lumen 52 is the venous lumen.

Referring to FIGS. 5-8, the catheter 50 defines the first and secondlumens 52, 54 with a lumen divider 56 between the two lumens 52, 54. Thecatheter 50 is preferably manufactured using a drawing techniquealthough other methods may be utilized. FIG. 6 illustrates the catheter50 after manufacture with the lumen divider 56 extending to the proximalend 51 of the catheter 50. To receive the distal end 16 of the adapter10, a portion of the lumen divider 56 must be removed to define areceiving notch 58 within the catheter proximal end 51. Preferably, thecenter portion of the divider 56 is removed while remaining portions 55,57 extend along each side of the notch 58. The remaining portions 55, 57are received in the respective grooves 33 of the adapter body 12 andhelp to ensure alignment of the adapter 10 relative to the catheter 50.

While the receiving notch 58 may be formed in the proximal end 51 of thecatheter 50 during the forming process, FIGS. 9-16 illustrate a pair ofexemplary tools 80, 80′ which may be utilized to form the receivingnotch 58 after the catheter 50 is formed but prior to assembly with theadapter 10. Each of the tools 80, 80′ include opposed jaws 82, 82′ and84, 84′ which are pivotal relative to each other about pivot point 86,86′. In the illustrated embodiments, the jaws 82, 82′ extend fromhandles 83, 83′ and the jaws 84, 84′ extend from handles 85, 85′ suchthat the jaws may be manually pivoted relative to one another, however,other mechanism, for example automated machines, may be utilized topivot the jaws relative to one another. In each jaw pair, one of thejaws 82, 82′ includes an extending cutting edge 88 while the other jaw84, 84′ includes a corresponding recess (not shown). The cutting edge 88has a shape corresponding to the desired shape of the receiving notch58. To make the notch 58, the jaws 82, 84; 82′, 84′ are positionedwithin the proximal end 51 of the catheter 50 in an open position asshown in FIGS. 11 and 15. In this way, the jaw 82, 82′ will enter thefirst lumen 52 and the jaw 84, 84′ will enter the second lumen 54 withthe divider 56 between the jaws. The jaws 82′ and 84′ include a recessedback 87 to facilitate positioning with the lumens. Once positioned, thejaws 82, 84; 82′, 84′ are pivoted to the closed position shown in FIGS.12 and 16 and the cutting edge 88, 88′ passes through the lumen divider56 and defines the notch 58. Other devices may alternatively be utilizedto define the notch 58.

Referring to FIGS. 17-18, once the receiving notch 58 is defined in theproximal end 51 of the catheter 50, the distal end 16 of the adapterbody 12 is positioned within the catheter 50 until the catheter 50engages the step 30. The catheter 50 extends about the connectionsurface 32, 32 a and is preferably secured thereto via bonding, welding,adhering or any other desired manner. As explained above, theinteraction of the divider remaining portions 55, 57 and the grooves 33will provide a rotational alignment feature. The adapter 10 only has tobe oriented properly such that the first hemisphere communicationportion 23 a is aligned with the first lumen 52 and the secondhemisphere communication portion 23 b is aligned with the second lumen54. The cutaway 34 defining the radial exit 22 a may be utilized toassist with such alignment.

With the adapter 10 secured to the proximal end 51 of the catheter 50,the assembly is ready for use. Prior to insertion of the stylet 70, itis typical procedure to flush both lumens 52, 54 of the catheter 50. Theadapter 10 facilitates easy flushing of both lumens 52, 54. A tip of asyringe or the like (not shown) is positioned through the entrance 20 ofthe passageway 18 into the connection portion 19. Since the firsthemisphere communication portion 23 a is aligned with the first lumen 52and the second hemisphere communication portion 23 b is aligned with thesecond lumen 54, the flushing fluid that is dispensed into thepassageway 18 simultaneously enters both lumens 52, 54 at asubstantially similar flow rate.

Once flushing is complete and the syringe is removed, the stylet shaft76 is positioned through the entrance 20 and into the passageway 18 asillustrated in FIG. 18. The taper of the transition portion 21 helps togenerally guide the stylet shaft 76 toward the central axis of thepassageway 18. If the stylet shaft 76 is directed toward the secondhemisphere communication portion 23 b, it will not be able to fit intothe ramp notch and instead will be guided by the ramp sides 43, 44toward the first hemisphere communication portion 23 a. Once alignedwith the first hemisphere communication portion 23 a, the stylet shaft76 passes through the radial outlet 22 a and into the first lumen 52.The stylet shaft 76 is passed until it exits the lumen 52 and the hubprojection 74 is receiving in the connection portion 19 of the adapterpassageway 18. The distal end of the catheter 50 is then inserted intothe vasculature by use of the stylet 70 in a known manner.

Once positioned, the stylet 70 is removed and discarded, and theproximal end 51 of the catheter assembly may be tunneled using atunneler 90. Referring to FIG. 20, an exemplary tunneler 90 is shownafter having been tunneled subcutaneously in a patient 100 to define atunnel 102 prior to connection to adapter 10. The exemplary tunneler 90has a rigid shaft 92 extending from a blunt tunneling tip 96 to a bluntconnection tip 94 adjacent to which is a connection section 98 having aplurality of barbs or annular projections that could be used to connectto a catheter lumen directly, but are also useful in establishing a firmconnection with adapter 10. Other types of tunnelers, for example, theRaulerson Ring Handled Y Adapter Tunneler sold by Medical Components,Inc. of Harleysville, Pa. may be utilized.

The tunneler 90 is connected to the adapter 10 by inserting theconnection section 98 into proximal entrance 20 of adapter 10. Theconnection section 98 engages the adapter body 12 within the connectionportion 19 of the passageway 18. The connection section 98 may form afairly permanent connection with the adapter 10 as the adapter 10 willbe cut from the catheter 50 after tunneling as described below. Onceconnected to the adapter 10, the tunneler 90 is pulled back through thetunnel 102 as shown in FIG. 21, thereby pulling the adapter 10 andcatheter 50 proximal end 51 through tunnel 102. Preferably the adapterbody 12 has a proximal end diameter which is equal to or less than theouter diameter of a guiding wedge 95 on the distal end of the tunneler90. Similarly, the outer diameter of the adapter body 12 at the step 30is greater than or equal to an outer diameter of the proximal end 51 ofthe catheter 50. In this way, the adapter 10 and catheter 50 are lesslikely to snag within the tunnel 102.

Referring to FIG. 22, after tunneling is completed, the proximal end 51of the catheter 50 is cut at 105 distally of the distal end 16 of theadapter 10. The cut 105 is preferably perpendicular to the axis of thecatheter 50. As illustrated, a single cut 105 will simultaneously leavetwo even lumens 52, 54. The severed portion of the catheter 50 and theadapter 10 may be discarded along with the tunneler 90.

Referring to FIGS. 23 and 24, connection of the catheter 50 to anexemplary hub assembly 110 will be described. The exemplary hub assembly110 is similar to that described in U.S. Pat. No. 6,969,381. The hubassembly 110 includes a pair of extension tube assemblies 112 and 114extending proximally from a hub base 111. The hub base 11 a fluidlyconnects each extension tube assembly 112, 114 with a respectivedistally extending cannula 116, 118. Each cannula 116, 118 is configuredto be received into a respective lumen 52, 54. The lumens 52, 54 aresecured the hub base 111 via a clamp assembly (not shown) which ispositioned over the catheter 50 and hub base 111.

It will be appreciated by those skilled in the art that changes could bemade to the embodiment described above without departing from the broadinventive concept thereof. It is understood, therefore, that thisinvention is not limited to the particular embodiment disclosed, but itis intended to cover modifications within the spirit and scope of thepresent invention as defined by the appended claims.

What is claimed is:
 1. A catheter tunneling adapter comprising: alongitudinal body having a distal end and a proximal end and apassageway extending from an entrance at the proximal end to an exit atthe distal end, the passageway having a first hemisphere and a secondhemisphere, with the first hemisphere defining a generally unobstructedfirst passageway portion from the entrance to the exit; and a guide ramppositioned within the second hemisphere and tapered towards the firsthemisphere moving from the proximal end to the distal end, the rampdefining a longitudinal notch therethrough such that a second passagewayportion extends from the entrance to the exit.
 2. The catheter tunnelingadapter according to claim 1, wherein the first passageway portion has adiameter greater than a width of the second passageway portion.
 3. Thecatheter tunneling adapter according to claim 1, wherein the passagewayentrance is configured to receive a portion of a syringe and a fluidexpelled from the syringe passes through and exits both the first andsecond passageway portions at the distal end of the longitudinal body.4. The catheter tunneling adapter according to claim 1, wherein thepassageway entrance is configured to securably receive a distal end of atunneler.
 5. The catheter tunneling adapter according to claim 1,wherein the distal end of the longitudinal body includes a radiallyinward step which defines a contact surface configured to be received ina proximal end of a catheter.
 6. The catheter tunneling adapteraccording to claim 5, wherein a portion of the contact surface adjacentthe first hemisphere is cutaway to define a radial exit.
 7. The cathetertunneling adapter according to claim 5, wherein opposed grooves aredefined in the contact surface from the distal end of the longitudinalbody to the radially inward step.
 8. The catheter tunneling adapteraccording to claim 1, wherein an outer surface of the longitudinal bodydefines one or more gripping recesses.
 9. The catheter tunneling adapteraccording to claim 1, wherein a reference plane separating the first andsecond hemispheres passes through a central axis of the passageway. 10.The catheter tunneling adapter according to claim 1, wherein a referenceplane separating the first and second hemispheres does not pass througha central axis of the passageway but instead is closer to the portion ofthe longitudinal body defining the first or second hemisphere.
 11. Thecatheter tunneling adapter according to claim 1, wherein the entrance ofthe passageway is configured to receive and connect with a connectionportion of a tunneler.
 12. An assembly comprising: a catheter extendingfrom a proximal end to a distal end and defining first and secondlumens; and a tunneling adapter including a longitudinal body having adistal end and a proximal end and a passageway extending from anentrance at the proximal end to an exit at the distal end, thepassageway having a first hemisphere and a second hemisphere, with thefirst hemisphere defining a generally unobstructed first passagewayportion from the entrance to the exit, the longitudinal body distal endsecured within the catheter proximal end; and a guide ramp positionedwithin the second hemisphere and tapered towards the first hemispheremoving from the proximal end to the distal end, the ramp defining alongitudinal notch therethrough such that a second passageway portionextends from the entrance to the exit.
 13. The assembly according toclaim 12, wherein the first passageway portion is aligned with the firstlumen and the second passageway portion is aligned with the secondlumen.
 14. The assembly according to claim 13, wherein the first lumenis an arterial lumen and the second lumen is venous lumen.
 15. Theassembly according to claim 12, wherein the passageway is configured forpassage of a stylet shaft having a given outer diameter therethrough,wherein the diameter of the first passageway portion is greater than thegiven outer diameter and the width of the second passageway portion isless than the given outer diameter.
 16. The assembly according to claim12, wherein the passageway entrance is configured to receive a portionof a syringe and a fluid expelled from the syringe passes through thefirst passageway portion and flows into the first lumen and also passesthrough the second passageway portion and into the second lumen.
 17. Theassembly according to claim 12, wherein the first and second lumens areseparated by a lumen divider, and wherein a proximal portion of thelumen divider is omitted to define an adapter receiving notch configuredto receive the distal end of the longitudinal body.
 18. The assemblyaccording to claim 17, wherein the distal end of the longitudinal bodyincludes a radially inward step which defines a contact surface which isreceived in the adapter receiving notch and the proximal end of thecatheter contacts the step.
 19. The assembly according to claim 18,wherein opposed side portions of the proximal lumen divider extend alongthe adapter receiving notch and are received in opposed grooves definedin the contact surface from the distal end of the longitudinal body tothe radially inward step.
 20. The assembly according to claim 18,wherein an outer diameter of the longitudinal body at the radiallyinward step is greater than or equal to an outer diameter of theproximal end of the catheter.